Coloured coating adapted for watch components

Abstract

Disclosed is a coating composition for watch elements, comprisinga binder, preferably a two-component polyurethane;one or more pigments, preferably in quantities from 19 to 58% by weight of pigments (based on total solids of the composition);at least one filler;a solvent or a solvent combination, preferably butyl acetate and/or ethyl lactate.optionally one or more commonly used additives, customary auxiliaries or combinations of them.Further disclosed are a kit-of-parts, a coating on a watch element, a process for coating a watch element and a watch obtainable by said process or comprising said coating.

The invention claimed is: 
     
       1. A watch element having a coating thereon, the coating, comprising
 a binder which is a two-component polyurethane; 
 one or more pigments; and 
 at least one filler; 
 wherein the watch element includes at least one recess and the coating is conformal to a geometry of the at least one recess. 
 
     
     
       2. The watch element according to  claim 1 , wherein the amount of pigment in the coating is 19 to 58 wt. % by weight based on total solids of the coating. 
     
     
       3. The watch element according to  claim 1 , wherein the coating has high scratch resistance, high durability and/or high optical covering power. 
     
     
       4. The watch element according to  claim 1 , wherein the coating has a mat, glossy or iridescent aspect. 
     
     
       5. A process for coating a watch element, wherein the coating is conformal, the process comprising the steps
 a) providing a substrate, the substrate having at least one recess; 
 b) optionally preparation of one or more homogeneous pastes; 
 c) optionally preparation of a pre-mix of different pastes obtained in step b); 
 d) preparation of a coating composition, the coating composition comprising: a binder which is a two-component polyurethane; one or more pigments; and at least one filler; 
 e) application of the coating composition onto the substrate such that the coating composition is conformal to the geometry of the at least one recess; 
 f) optionally drying 
 g) curing of the coating composition to form the coating. 
 
     
     
       6. A watch element obtainable by the process of  claim 5 . 
     
     
       7. The process according to  claim 5 , wherein the one or more homogenous pastes is a colour paste and/or a filler paste. 
     
     
       8. The watch element of  claim 1 , wherein the coating comprises an intense color, a dynamic modulus of >10 9  Pa measured by Dynamic Mechanical Analysis (DMA), a resistance to humidity of 0.4 to 0.6% of water intake with an isotherm of 24 h at 40° C. and 60% RH, measured by Dynamic Vapor Sorption (DVS), and a T g  of between 55 and 71° C., measured by Differential Scanning calorimetry under nitrogen (DSC). 
     
     
       9. The watch element of  claim 1 , wherein the coating composition includes a solvent configured to obtain a suitable viscosity and control an evaporation rate of the coating composition. 
     
     
       10. The watch element of  claim 1 , wherein the one or more pigments includes a pigment paste comprising polyol. 
     
     
       11. The process according to  claim 5 , wherein during application of the coating composition into a recess, a deposited volume is adjusted to a volume of the recess. 
     
     
       12. The process according to  claim 5 , wherein preparation of the coating composition includes having 19 to 58 wt. % pigments based on total solids. 
     
     
       13. The process according to  claim 5 , wherein the cured coating has an intense colour. 
     
     
       14. The watch element of  claim 1 , wherein the two-component polyurethane is based on an aliphatic diisocyanate and a polyol. 
     
     
       15. The watch element of  claim 14 , wherein the polyol has an OH content of 6 to 9% or an OH number between 50 and 240 mg KOH. 
     
     
       16. The watch element of  claim 14 , wherein the polyol is a polyester polyol or a polyether polyol. 
     
     
       17. The watch element of  claim 14 , wherein the aliphatic diisocyanate is isophorone diisocyanate or 4,4′-diisocyanatodicyclohexylmethan.